Solid Detergent is one of the Economic materials and Environmentally friendly method towards enha... more Solid Detergent is one of the Economic materials and Environmentally friendly method towards enhancing properties of concrete. Lightweight, slow reaction and anti acid concrete can achieving by using this materials, so many test made to validate the advantage and disadvantage ; initial and final hardening time for cement mortar and compressive strength of concrete, also anti acid test made for cement mortar. The results of tests show this materials are suitable for achieving the purpose to lightweight, slow reaction additional anti acid concrete.
The presence of the openings negatively effects on the strength of the beams where they act as a... more The presence of the openings negatively effects on the strength of the beams where they act as a weak point because of the sudden change in the cross-section of the beam, so it becomes necessary to make strengthening for the beams to resist the effect of the openings and improve the strength of the beams, especially if the beams are subjected to repeated loads because of its effect on the strength at the failure. This paper studies the effect of the openings on the beams subjected to repeated loading and determine the extent of the increase in the strength of the beams when strengthened by the NSM technique. The experimental program included casting and testing fifteen RC beams, six of them considered as a control beams (three with strengthening and three without strengthening), and nine of them having circular transverse openings in different locations and strengthened by the NSM technique. Every type of beams is tested under three different types of loads (monotonic, constant rep...
The present study is about an experimental investigation of the strength and response of reinforc... more The present study is about an experimental investigation of the strength and response of reinforced concrete tapered beams strengthened by near surface mounting (NSM)-CFRP technique. The influence of several parameters on the behavior of beams is investigated. And those parameters are: angle of inclination and strengthening patterns by NSM-CFRP technique. The experimental program involved testing nine specimens of reinforced concrete tapered beams and one prismatic beam. There were two groups in the experimental program; the first group included four unstrengthening reference beams to investigate the effect the angle of inclination, and the second group included six specimens were strengthened by NSM-CFRP strips with different strengthening patterns (U-strips) and (UL-strips) were used to strengthen the tapered beams against shear and flexural forces. The results of the experiments indicated that as the angle of inclination increased, from (0˚) to (7°), (14°) and (21°) decreases the...
Background: Cigarette smoking and Nicotine dependence are highly prevalent in patients with sever... more Background: Cigarette smoking and Nicotine dependence are highly prevalent in patients with severe and chronic mental illness. Psychiatric patients consume more cigarettes than general population. Smokers with chronic mental illness can quit smoking with appropriate intervention by smoking cessations programs. These patients can benefit from pharmacotherapy, but consideration should be given for possible interaction with patients’ psychiatric medications. Tobacco use and dependence need to be formally documents on electronic medical records and be offered a referral to smoking cessations programs. Method: All patients in a community rehabilitation service ward in Northwest London were interviewed to identify the type, quantity, and duration of their tobacco. Their electronic clinical records were reviewed to confirm their age, ICD 10 Primary Diagnosis, ICD10 Tobacco dependence diagnosis, medications they take, record of ECG tests and presence of cardiopulmonary problems. Then their ...
In this research, the effect of the addition of fly ash particles with different weight ratios of... more In this research, the effect of the addition of fly ash particles with different weight ratios of 15%, 20%, and 25% as well as the addition steel fibers with different volume fractions of 0.25%, 0.75%, and 1.25% on the mechanical properties of concrete (compressive strength and modulus of rupture) was studied. To carry out this research, ten concrete mixes were prepared, one of which is the reference normal concrete (without any additives), the others contain steel fibers and fly ash as additives with the mentioned volumetric and weight proportions. For each type of concrete mix, three standard 150×300 mm cylinders and three standard prisms 100×100×500 mm were casted, water to cementing material ratio was fixed for all concrete mixes (W/cm = 0.435) and the superplasticizer was used with ratio of 0.98%-1.22% by weight of the cementitious material in mixtures that contain steel fibers and fly ash particles as a partial replacement of cement weight. The results showed that the addition...
Rainwater harvesting and flood prevention in cities are significant urban hydrological concerns. ... more Rainwater harvesting and flood prevention in cities are significant urban hydrological concerns. The use of porous pavement is one of the most effective solutions to handle this matter. Thus, this study aims to develop Porous Interlocking Concrete Pavement (PICP) using recycled aggregate from concrete waste. This porous pavement, then later, can be utilized in low traffic areas and parking lots to harvest water by infiltration and reduce surface runoff. First, the physical properties of the porous concrete blocks, such as density (unit weight), absorption, coefficient of permeability, and porosity, were studied. Also, the mechanical properties of concrete mixtures like compressive strength and flexural strength were tested. This study used two types of PICP, the first one with ordinary coarse aggregate (P1) and the second with recycled crushed concrete coarse aggregate (P2), and then compared their performance to the conventional concrete pavement blocks used the two types of coarse...
IOP Conference Series: Materials Science and Engineering
This work is an experimental investigation about the properties of sand-powder adhesive subjected... more This work is an experimental investigation about the properties of sand-powder adhesive subjected to high temperature. Thus, three main mixtures were tested. These mixes contain three different sand to adhesive ratios; 0:1, 1:1 and 1.5:1. The Simultaneous of Thermal Analyzers (STA); represent real-time measurement, change of sample weight analysis and heat flow were investigated. The results indicated that the physicochemical properties (residual mechanical properties, residual weight, weight losing rate, glass transition temperature (Tg), Carbonate point or extrapolated onset temperature (To), and heat flow) have been remarkably enhanced by the addition of sand-powder. The addition of sand resulted in increased epoxy resistance to high heat. When the sand-powder exposed to 550 ° C, the weight loss of the epoxy was 52%, 30% and 25% for sand to adhesive ratios equal to 0, 1, and 1.5 % respectively. In other words, the epoxy containing a high proportion of sand retained 25% of its wei...
Abstract In this study, a total of 13 FRP-strengthened reinforced concrete beams were tested in f... more Abstract In this study, a total of 13 FRP-strengthened reinforced concrete beams were tested in flexure and analyzed using the finite element method. The various variables included bonding or no bonding of the FRP, the anchorage system, the amount of prestressing, and the span length. The experiments consisted of one control beam, two non-prestressed FRP-bonded beams, four prestressed FRP-unbonded beams, four prestressed FRP-bonded beams, and two prestressed FRP-unbonded beams with different span lengths. All the beams were subjected to three-point and four-point bending tests under deflection control, with the loading, deflection and failure modes recorded to the point of failure. A nonlinear finite element analysis of the tested beams was also performed using the DIANA software; this analysis accounted for the nonlinear concrete material behaviour, the reinforcement, and an interfacial bond-slip model between the concrete and CFRP plates. The aim of this investigation was to study the flexural performance of reinforced concrete members strengthened using CFRP plates, employing different FRP bonding and prestressing methods. The failure mode of the prestressed CFRP-plated beams was not debonding, but FRP rupture. For the reinforced concrete members strengthened with externally bonded prestressed CFRP plates, debonding of the composite laminates occurred in two stages. After the debonding of the CFRP plates that occurred in the bonded cases, the behaviour of the bonded CFRP-plated beams changed to that of the unbonded CFRP-plated beams due to the effect of the anchorage system. The flexural test results and analytical predictions for the CFRP-strengthened beams were compared and showed very good agreement in terms of the debonding load, yield load, and ultimate load. The ductility of the beams strengthened with CFRP plates having the anchorage system was considered high if the ductility index was above 3.
In modern buildings, transverse openings are often used beams for the purpose of supplying and se... more In modern buildings, transverse openings are often used beams for the purpose of supplying and service pipes. Due to the presence of the openings in the concrete beams lead to the formation of cracks around the openings due to the stresses concentration in a small area above and below of the opening. The repairing, maintenance, and upgrading of structural members, are maybe one of the most pivotal problems in civil engineering applications. In this research, an experimental work is conducted to study the behavior of the reinforced RPC T-beams that containing openings and repair this beams using CFRP strips. The Experimental program of the present study includes two parts, the first part includes testing of seven reinforced reactive powder concrete RPC T-beams, which casted and tested, one beam is without opening as a reference beam and the rest, were provided with an opening. and these beams are divided into two groups. The first group was used to study the effect of the openings sh...
This research aims to investigate experimentally the structural response of ferrocement slabs mad... more This research aims to investigate experimentally the structural response of ferrocement slabs made with modified reactive powder concrete subjected to concentrated loading. The experimental work consist of casting and testing twelve ferrocement slabs of dimensions (500*500*50) mm made with reactive powder concrete (contains Fly Ash as pozzolanic material) to enhance the strength of the ferrocement slabs. The parametric study adopted in this work includes using of three volumetric percentage ratio (0% , 0.5% and 1%) and the two number of wire mesh layers (2 and 4) as well as two fly ash ratios (0% and 10%). For the different RPC mixes, three cubes (70 mm) and three prisms (40*40*160)mm were cast and tested to determine the compressive strength and modulus of rupture. The comparisons between all specimens are based on first crack load, ultimate load carrying capacity, deflection, crack pattern and mode of failures. Results showed that the steel fibers, wire meshes and fly ash have a s...
In this research, an experimental study is conducted to investigate the behavior and strength of ... more In this research, an experimental study is conducted to investigate the behavior and strength of high strength reinforced concrete corbels externally bonded with CFRP fabric sheets and Plates with different patterns taking into account the effect of adopted variables in enhancing the ultimate strength; the effect of shear span to effective depth (a/d), configuration, type and amount of bonding. Eleven high strength reinforced corbels were cast and tested under vertical loads. Test results showed there was an improvement in the behavior and load carrying capacity of all strengthened corbels. An increasing in the ultimate strength of strengthened corbel by inclined CFRP strips reached to (92.1%) while the increasing reached to (84.21%) for using one horizontal CFRP Plates compared to un-strengthened reference specimen. Also, it can be conducted that the increase of (a/d) ratio from (0.6 to 0.8) resulted in decreasing by 21.05% in ultimate load capacity of corbels and from (0.4 to 0.6)...
IOP Conference Series: Materials Science and Engineering
This work is an experimental investigation about the properties of sand-powder adhesive subjected... more This work is an experimental investigation about the properties of sand-powder adhesive subjected to high temperature. Thus, three main mixtures were tested. These mixes contain three different sand to adhesive ratios; 0:1, 1:1 and 1.5:1. The Simultaneous of Thermal Analyzers (STA); represent real-time measurement, change of sample weight analysis and heat flow were investigated. The results indicated that the physicochemical properties (residual mechanical properties, residual weight, weight losing rate, glass transition temperature (Tg), Carbonate point or extrapolated onset temperature (To), and heat flow) have been remarkably enhanced by the addition of sand-powder. The addition of sand resulted in increased epoxy resistance to high heat. When the sand-powder exposed to 550 ° C, the weight loss of the epoxy was 52%, 30% and 25% for sand to adhesive ratios equal to 0, 1, and 1.5 % respectively. In other words, the epoxy containing a high proportion of sand retained 25% of its wei...
A finite element model for the study of the creep, shrinkage and tensile stiffness between cracks... more A finite element model for the study of the creep, shrinkage and tensile stiffness between cracks effects in partially prestressed continuous composite beams with deformable shear connections is proposed in this paper. The algorithm used is very general and allows the adoption of an arbitrary viscous law expressed in integral form and any load history. By means of simple numerical comparisons, the potentials of the proposed formulation are shown. This model, due to its simplicity, can be easy implemented in an analytical program.
In modern buildings, transverse openings are often used in order to pass the pipes of health serv... more In modern buildings, transverse openings are often used in order to pass the pipes of health services, electrical cables or air conditioning ducts and other prepuce. The presence of these openings leads to a weakening of the beam so it must work to investigate the behavior of these beams in order to know how the presence of openings affects beam resistance. In this research, the behavior of reinforced concrete T-beams with circular openings exposed to pure torsional moment is studied. The experimental program involves testing of five beams with same dimensions and reinforcements. One of them is solid beam and used as reference for comparison with other beams with an opening and the other four T- beams containing circular openings of deferent dimension(100 and 150) and location(Lc/2 and Lc/3). Practical results show that the Tbeam with circular openings of diameter (100mm) with different locations (Lc/2 and Lc/3), where Lc is the clear span of the beam, have an ultimate torsional cap...
This research is devoted to investigating experimentally the punching shear strength of reactive ... more This research is devoted to investigating experimentally the punching shear strength of reactive powder concrete slabs under monotonic loading. All slabs have the same flexural reinforcement and same dimensions (1000mm length,600mm width,50mm thickness). The experimental program includes casting and testing of sixteen slabs tested under monotonic loading. The major parameters adopted in the current research include the shape of column (circle, square), column size (twocolumn sizes), number of columns (one, two), and the distance between two columns (3d,5d,7d). Results showed that, the slabs with circular column sections have slightly higher ultimate load than those with square column sections. An increasing column area increases the load of punching shear failure. It was found that the ultimate failure load for slabs with two columns is greater than the slabs with one column. Related to the effect of distance between the two columns for monotonic, it was found that the slabs maximum...
IOP Conference Series: Materials Science and Engineering
In this research, the response of reactive powder concrete T-beams containing openings is studied... more In this research, the response of reactive powder concrete T-beams containing openings is studied. The experimental program involves testing of thirteen simply supported beams. The beams have the same dimensions, flexural and shear reinforcements. In this study, four three parameters have been studied: the shape of an opening (circular and square), a location of openings from the support (Lc/2, Lc/3, and Lc/4), and the internally strengthened around of opening using a deformed steel bar. The experimental results showed that the RPC T-beams with circular openings of diameter (110mm) with different locations (Lc/2, Lc/3 and Lc/4) have a flexural strength less than that solid beam by about (12%,35%and 41%) respectively. While for the RPC T-beams with square openings of dimension (100mm×100mm) with different locations (Lc/2, Lc/3, and Lc/4), the flexural strength is less than that solid beams by (10%,41%and 55%) respectively. In addition, it is found that the use of deformed steel bars ...
Abstract Despite the superior properties of reactive powder concrete (RPC), the possibility of sp... more Abstract Despite the superior properties of reactive powder concrete (RPC), the possibility of spalling under fire conditions still exists, which can lead to a significant reduction in the fire endurance of reinforced concrete members. This study investigates the efficiency of using the different percentages of polypropylene fibres (PPFs) for enhancing the fire resistance of reinforced beams made from RPC. Five RPC beams were tested by applying two concentrated loads. One of them (without PPFs) was tested under monotonic load up to failure. The other four beams were subjected to service load, and then controlled fire was applied for 120 min in accordance with the fire temperature vs. time curve prescribed in ASTM E 119. Loading tests were then conducted on the beams that were not completely damaged through fire testing, in order to examine their remaining strength after cooling. Experimental results showed that non-fibrous reinforced RPC beams suffer early spalling during the fire test, thus causing beam failure after 38 min of fire exposure. The addition of PPFs in a low volume percentage (0.25%) decreases spalling and delays beam failure until 115 min, whereas PPFs in high percentages (0.75% and 1.25%) completely prevent the spalling and beam collapse. Moreover, an increase in PPF content reduces the total deflection of a beam and improves the residual strength and ultimate strength of fire-failed beams subsequent to cooling.
Roofing elements is one of the most widely used applications of folded ferrocement for both indus... more Roofing elements is one of the most widely used applications of folded ferrocement for both industrial and domestic buildings. Owing to this wide application, more advanced mechanical properties are required for these elements. Among these mechanical properties, mechanical capacity against fracture and harsh climate are two essential properties must be acquired. Thus, the present investigation was conducted to fabricate a high strength and environmental resist folded ferrocement elements. Cubes of the specimens were prepared by folding technique at 50×50×50 mm size with specific enforcement. These samples were exposed to hot environment at different time intervals then examined for compressive strength. Also, the modulus of rupture for the standard prisms of 40×40×160 mm prepared and examined at different temperatures-time strategies. It was found that the preparation method of folding gave a high quality folded ferrocement in terms of flexural and climate resistance. It was also fo...
Reactive Powder Concrete (RPC) is an ultra-high performance concrete which has superior mechanica... more Reactive Powder Concrete (RPC) is an ultra-high performance concrete which has superior mechanical and physical properties, and composed of cement and very fine powders such as quartz sand and silica fume with very low water/ binder ratio and Superplasticizer. Heat treatment is a well-known method that can further improve the performance of (RPC). The current research including an experimental study of the effect of different curing conditions on mechanical properties of reactive powder concrete (compressive strength, modulus of rupture and splitting tensile strength), the curing conditions includes three type of curing; immersion in water at temperature of 35 OC (which is considered as the reference-curing situation), immersion in water at temperature of 90 OC for 5 hours daily and curing with hot steam for 5 hours daily) until 28 days according to ASTM C684-99 [8]. This research includes also the study of effect of adding silica fume as percentage of cement weight on mechanical pr...
Solid Detergent is one of the Economic materials and Environmentally friendly method towards enha... more Solid Detergent is one of the Economic materials and Environmentally friendly method towards enhancing properties of concrete. Lightweight, slow reaction and anti acid concrete can achieving by using this materials, so many test made to validate the advantage and disadvantage ; initial and final hardening time for cement mortar and compressive strength of concrete, also anti acid test made for cement mortar. The results of tests show this materials are suitable for achieving the purpose to lightweight, slow reaction additional anti acid concrete.
The presence of the openings negatively effects on the strength of the beams where they act as a... more The presence of the openings negatively effects on the strength of the beams where they act as a weak point because of the sudden change in the cross-section of the beam, so it becomes necessary to make strengthening for the beams to resist the effect of the openings and improve the strength of the beams, especially if the beams are subjected to repeated loads because of its effect on the strength at the failure. This paper studies the effect of the openings on the beams subjected to repeated loading and determine the extent of the increase in the strength of the beams when strengthened by the NSM technique. The experimental program included casting and testing fifteen RC beams, six of them considered as a control beams (three with strengthening and three without strengthening), and nine of them having circular transverse openings in different locations and strengthened by the NSM technique. Every type of beams is tested under three different types of loads (monotonic, constant rep...
The present study is about an experimental investigation of the strength and response of reinforc... more The present study is about an experimental investigation of the strength and response of reinforced concrete tapered beams strengthened by near surface mounting (NSM)-CFRP technique. The influence of several parameters on the behavior of beams is investigated. And those parameters are: angle of inclination and strengthening patterns by NSM-CFRP technique. The experimental program involved testing nine specimens of reinforced concrete tapered beams and one prismatic beam. There were two groups in the experimental program; the first group included four unstrengthening reference beams to investigate the effect the angle of inclination, and the second group included six specimens were strengthened by NSM-CFRP strips with different strengthening patterns (U-strips) and (UL-strips) were used to strengthen the tapered beams against shear and flexural forces. The results of the experiments indicated that as the angle of inclination increased, from (0˚) to (7°), (14°) and (21°) decreases the...
Background: Cigarette smoking and Nicotine dependence are highly prevalent in patients with sever... more Background: Cigarette smoking and Nicotine dependence are highly prevalent in patients with severe and chronic mental illness. Psychiatric patients consume more cigarettes than general population. Smokers with chronic mental illness can quit smoking with appropriate intervention by smoking cessations programs. These patients can benefit from pharmacotherapy, but consideration should be given for possible interaction with patients’ psychiatric medications. Tobacco use and dependence need to be formally documents on electronic medical records and be offered a referral to smoking cessations programs. Method: All patients in a community rehabilitation service ward in Northwest London were interviewed to identify the type, quantity, and duration of their tobacco. Their electronic clinical records were reviewed to confirm their age, ICD 10 Primary Diagnosis, ICD10 Tobacco dependence diagnosis, medications they take, record of ECG tests and presence of cardiopulmonary problems. Then their ...
In this research, the effect of the addition of fly ash particles with different weight ratios of... more In this research, the effect of the addition of fly ash particles with different weight ratios of 15%, 20%, and 25% as well as the addition steel fibers with different volume fractions of 0.25%, 0.75%, and 1.25% on the mechanical properties of concrete (compressive strength and modulus of rupture) was studied. To carry out this research, ten concrete mixes were prepared, one of which is the reference normal concrete (without any additives), the others contain steel fibers and fly ash as additives with the mentioned volumetric and weight proportions. For each type of concrete mix, three standard 150×300 mm cylinders and three standard prisms 100×100×500 mm were casted, water to cementing material ratio was fixed for all concrete mixes (W/cm = 0.435) and the superplasticizer was used with ratio of 0.98%-1.22% by weight of the cementitious material in mixtures that contain steel fibers and fly ash particles as a partial replacement of cement weight. The results showed that the addition...
Rainwater harvesting and flood prevention in cities are significant urban hydrological concerns. ... more Rainwater harvesting and flood prevention in cities are significant urban hydrological concerns. The use of porous pavement is one of the most effective solutions to handle this matter. Thus, this study aims to develop Porous Interlocking Concrete Pavement (PICP) using recycled aggregate from concrete waste. This porous pavement, then later, can be utilized in low traffic areas and parking lots to harvest water by infiltration and reduce surface runoff. First, the physical properties of the porous concrete blocks, such as density (unit weight), absorption, coefficient of permeability, and porosity, were studied. Also, the mechanical properties of concrete mixtures like compressive strength and flexural strength were tested. This study used two types of PICP, the first one with ordinary coarse aggregate (P1) and the second with recycled crushed concrete coarse aggregate (P2), and then compared their performance to the conventional concrete pavement blocks used the two types of coarse...
IOP Conference Series: Materials Science and Engineering
This work is an experimental investigation about the properties of sand-powder adhesive subjected... more This work is an experimental investigation about the properties of sand-powder adhesive subjected to high temperature. Thus, three main mixtures were tested. These mixes contain three different sand to adhesive ratios; 0:1, 1:1 and 1.5:1. The Simultaneous of Thermal Analyzers (STA); represent real-time measurement, change of sample weight analysis and heat flow were investigated. The results indicated that the physicochemical properties (residual mechanical properties, residual weight, weight losing rate, glass transition temperature (Tg), Carbonate point or extrapolated onset temperature (To), and heat flow) have been remarkably enhanced by the addition of sand-powder. The addition of sand resulted in increased epoxy resistance to high heat. When the sand-powder exposed to 550 ° C, the weight loss of the epoxy was 52%, 30% and 25% for sand to adhesive ratios equal to 0, 1, and 1.5 % respectively. In other words, the epoxy containing a high proportion of sand retained 25% of its wei...
Abstract In this study, a total of 13 FRP-strengthened reinforced concrete beams were tested in f... more Abstract In this study, a total of 13 FRP-strengthened reinforced concrete beams were tested in flexure and analyzed using the finite element method. The various variables included bonding or no bonding of the FRP, the anchorage system, the amount of prestressing, and the span length. The experiments consisted of one control beam, two non-prestressed FRP-bonded beams, four prestressed FRP-unbonded beams, four prestressed FRP-bonded beams, and two prestressed FRP-unbonded beams with different span lengths. All the beams were subjected to three-point and four-point bending tests under deflection control, with the loading, deflection and failure modes recorded to the point of failure. A nonlinear finite element analysis of the tested beams was also performed using the DIANA software; this analysis accounted for the nonlinear concrete material behaviour, the reinforcement, and an interfacial bond-slip model between the concrete and CFRP plates. The aim of this investigation was to study the flexural performance of reinforced concrete members strengthened using CFRP plates, employing different FRP bonding and prestressing methods. The failure mode of the prestressed CFRP-plated beams was not debonding, but FRP rupture. For the reinforced concrete members strengthened with externally bonded prestressed CFRP plates, debonding of the composite laminates occurred in two stages. After the debonding of the CFRP plates that occurred in the bonded cases, the behaviour of the bonded CFRP-plated beams changed to that of the unbonded CFRP-plated beams due to the effect of the anchorage system. The flexural test results and analytical predictions for the CFRP-strengthened beams were compared and showed very good agreement in terms of the debonding load, yield load, and ultimate load. The ductility of the beams strengthened with CFRP plates having the anchorage system was considered high if the ductility index was above 3.
In modern buildings, transverse openings are often used beams for the purpose of supplying and se... more In modern buildings, transverse openings are often used beams for the purpose of supplying and service pipes. Due to the presence of the openings in the concrete beams lead to the formation of cracks around the openings due to the stresses concentration in a small area above and below of the opening. The repairing, maintenance, and upgrading of structural members, are maybe one of the most pivotal problems in civil engineering applications. In this research, an experimental work is conducted to study the behavior of the reinforced RPC T-beams that containing openings and repair this beams using CFRP strips. The Experimental program of the present study includes two parts, the first part includes testing of seven reinforced reactive powder concrete RPC T-beams, which casted and tested, one beam is without opening as a reference beam and the rest, were provided with an opening. and these beams are divided into two groups. The first group was used to study the effect of the openings sh...
This research aims to investigate experimentally the structural response of ferrocement slabs mad... more This research aims to investigate experimentally the structural response of ferrocement slabs made with modified reactive powder concrete subjected to concentrated loading. The experimental work consist of casting and testing twelve ferrocement slabs of dimensions (500*500*50) mm made with reactive powder concrete (contains Fly Ash as pozzolanic material) to enhance the strength of the ferrocement slabs. The parametric study adopted in this work includes using of three volumetric percentage ratio (0% , 0.5% and 1%) and the two number of wire mesh layers (2 and 4) as well as two fly ash ratios (0% and 10%). For the different RPC mixes, three cubes (70 mm) and three prisms (40*40*160)mm were cast and tested to determine the compressive strength and modulus of rupture. The comparisons between all specimens are based on first crack load, ultimate load carrying capacity, deflection, crack pattern and mode of failures. Results showed that the steel fibers, wire meshes and fly ash have a s...
In this research, an experimental study is conducted to investigate the behavior and strength of ... more In this research, an experimental study is conducted to investigate the behavior and strength of high strength reinforced concrete corbels externally bonded with CFRP fabric sheets and Plates with different patterns taking into account the effect of adopted variables in enhancing the ultimate strength; the effect of shear span to effective depth (a/d), configuration, type and amount of bonding. Eleven high strength reinforced corbels were cast and tested under vertical loads. Test results showed there was an improvement in the behavior and load carrying capacity of all strengthened corbels. An increasing in the ultimate strength of strengthened corbel by inclined CFRP strips reached to (92.1%) while the increasing reached to (84.21%) for using one horizontal CFRP Plates compared to un-strengthened reference specimen. Also, it can be conducted that the increase of (a/d) ratio from (0.6 to 0.8) resulted in decreasing by 21.05% in ultimate load capacity of corbels and from (0.4 to 0.6)...
IOP Conference Series: Materials Science and Engineering
This work is an experimental investigation about the properties of sand-powder adhesive subjected... more This work is an experimental investigation about the properties of sand-powder adhesive subjected to high temperature. Thus, three main mixtures were tested. These mixes contain three different sand to adhesive ratios; 0:1, 1:1 and 1.5:1. The Simultaneous of Thermal Analyzers (STA); represent real-time measurement, change of sample weight analysis and heat flow were investigated. The results indicated that the physicochemical properties (residual mechanical properties, residual weight, weight losing rate, glass transition temperature (Tg), Carbonate point or extrapolated onset temperature (To), and heat flow) have been remarkably enhanced by the addition of sand-powder. The addition of sand resulted in increased epoxy resistance to high heat. When the sand-powder exposed to 550 ° C, the weight loss of the epoxy was 52%, 30% and 25% for sand to adhesive ratios equal to 0, 1, and 1.5 % respectively. In other words, the epoxy containing a high proportion of sand retained 25% of its wei...
A finite element model for the study of the creep, shrinkage and tensile stiffness between cracks... more A finite element model for the study of the creep, shrinkage and tensile stiffness between cracks effects in partially prestressed continuous composite beams with deformable shear connections is proposed in this paper. The algorithm used is very general and allows the adoption of an arbitrary viscous law expressed in integral form and any load history. By means of simple numerical comparisons, the potentials of the proposed formulation are shown. This model, due to its simplicity, can be easy implemented in an analytical program.
In modern buildings, transverse openings are often used in order to pass the pipes of health serv... more In modern buildings, transverse openings are often used in order to pass the pipes of health services, electrical cables or air conditioning ducts and other prepuce. The presence of these openings leads to a weakening of the beam so it must work to investigate the behavior of these beams in order to know how the presence of openings affects beam resistance. In this research, the behavior of reinforced concrete T-beams with circular openings exposed to pure torsional moment is studied. The experimental program involves testing of five beams with same dimensions and reinforcements. One of them is solid beam and used as reference for comparison with other beams with an opening and the other four T- beams containing circular openings of deferent dimension(100 and 150) and location(Lc/2 and Lc/3). Practical results show that the Tbeam with circular openings of diameter (100mm) with different locations (Lc/2 and Lc/3), where Lc is the clear span of the beam, have an ultimate torsional cap...
This research is devoted to investigating experimentally the punching shear strength of reactive ... more This research is devoted to investigating experimentally the punching shear strength of reactive powder concrete slabs under monotonic loading. All slabs have the same flexural reinforcement and same dimensions (1000mm length,600mm width,50mm thickness). The experimental program includes casting and testing of sixteen slabs tested under monotonic loading. The major parameters adopted in the current research include the shape of column (circle, square), column size (twocolumn sizes), number of columns (one, two), and the distance between two columns (3d,5d,7d). Results showed that, the slabs with circular column sections have slightly higher ultimate load than those with square column sections. An increasing column area increases the load of punching shear failure. It was found that the ultimate failure load for slabs with two columns is greater than the slabs with one column. Related to the effect of distance between the two columns for monotonic, it was found that the slabs maximum...
IOP Conference Series: Materials Science and Engineering
In this research, the response of reactive powder concrete T-beams containing openings is studied... more In this research, the response of reactive powder concrete T-beams containing openings is studied. The experimental program involves testing of thirteen simply supported beams. The beams have the same dimensions, flexural and shear reinforcements. In this study, four three parameters have been studied: the shape of an opening (circular and square), a location of openings from the support (Lc/2, Lc/3, and Lc/4), and the internally strengthened around of opening using a deformed steel bar. The experimental results showed that the RPC T-beams with circular openings of diameter (110mm) with different locations (Lc/2, Lc/3 and Lc/4) have a flexural strength less than that solid beam by about (12%,35%and 41%) respectively. While for the RPC T-beams with square openings of dimension (100mm×100mm) with different locations (Lc/2, Lc/3, and Lc/4), the flexural strength is less than that solid beams by (10%,41%and 55%) respectively. In addition, it is found that the use of deformed steel bars ...
Abstract Despite the superior properties of reactive powder concrete (RPC), the possibility of sp... more Abstract Despite the superior properties of reactive powder concrete (RPC), the possibility of spalling under fire conditions still exists, which can lead to a significant reduction in the fire endurance of reinforced concrete members. This study investigates the efficiency of using the different percentages of polypropylene fibres (PPFs) for enhancing the fire resistance of reinforced beams made from RPC. Five RPC beams were tested by applying two concentrated loads. One of them (without PPFs) was tested under monotonic load up to failure. The other four beams were subjected to service load, and then controlled fire was applied for 120 min in accordance with the fire temperature vs. time curve prescribed in ASTM E 119. Loading tests were then conducted on the beams that were not completely damaged through fire testing, in order to examine their remaining strength after cooling. Experimental results showed that non-fibrous reinforced RPC beams suffer early spalling during the fire test, thus causing beam failure after 38 min of fire exposure. The addition of PPFs in a low volume percentage (0.25%) decreases spalling and delays beam failure until 115 min, whereas PPFs in high percentages (0.75% and 1.25%) completely prevent the spalling and beam collapse. Moreover, an increase in PPF content reduces the total deflection of a beam and improves the residual strength and ultimate strength of fire-failed beams subsequent to cooling.
Roofing elements is one of the most widely used applications of folded ferrocement for both indus... more Roofing elements is one of the most widely used applications of folded ferrocement for both industrial and domestic buildings. Owing to this wide application, more advanced mechanical properties are required for these elements. Among these mechanical properties, mechanical capacity against fracture and harsh climate are two essential properties must be acquired. Thus, the present investigation was conducted to fabricate a high strength and environmental resist folded ferrocement elements. Cubes of the specimens were prepared by folding technique at 50×50×50 mm size with specific enforcement. These samples were exposed to hot environment at different time intervals then examined for compressive strength. Also, the modulus of rupture for the standard prisms of 40×40×160 mm prepared and examined at different temperatures-time strategies. It was found that the preparation method of folding gave a high quality folded ferrocement in terms of flexural and climate resistance. It was also fo...
Reactive Powder Concrete (RPC) is an ultra-high performance concrete which has superior mechanica... more Reactive Powder Concrete (RPC) is an ultra-high performance concrete which has superior mechanical and physical properties, and composed of cement and very fine powders such as quartz sand and silica fume with very low water/ binder ratio and Superplasticizer. Heat treatment is a well-known method that can further improve the performance of (RPC). The current research including an experimental study of the effect of different curing conditions on mechanical properties of reactive powder concrete (compressive strength, modulus of rupture and splitting tensile strength), the curing conditions includes three type of curing; immersion in water at temperature of 35 OC (which is considered as the reference-curing situation), immersion in water at temperature of 90 OC for 5 hours daily and curing with hot steam for 5 hours daily) until 28 days according to ASTM C684-99 [8]. This research includes also the study of effect of adding silica fume as percentage of cement weight on mechanical pr...
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